diff options
Diffstat (limited to 'include/asm-powerpc/page.h')
| -rw-r--r-- | include/asm-powerpc/page.h | 45 |
1 files changed, 37 insertions, 8 deletions
diff --git a/include/asm-powerpc/page.h b/include/asm-powerpc/page.h index 6c850609b847..cffdf0eb0df6 100644 --- a/include/asm-powerpc/page.h +++ b/include/asm-powerpc/page.h @@ -12,6 +12,7 @@ #include <asm/asm-compat.h> #include <asm/kdump.h> +#include <asm/types.h> /* * On PPC32 page size is 4K. For PPC64 we support either 4K or 64K software @@ -42,8 +43,23 @@ * * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET. * - * To get a physical address from a virtual one you subtract PAGE_OFFSET, - * _not_ KERNELBASE. + * PAGE_OFFSET is the virtual address of the start of lowmem. + * + * PHYSICAL_START is the physical address of the start of the kernel. + * + * MEMORY_START is the physical address of the start of lowmem. + * + * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on + * ppc32 and based on how they are set we determine MEMORY_START. + * + * For the linear mapping the following equation should be true: + * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START + * + * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START + * + * There are two was to determine a physical address from a virtual one: + * va = pa + PAGE_OFFSET - MEMORY_START + * va = pa + KERNELBASE - PHYSICAL_START * * If you want to know something's offset from the start of the kernel you * should subtract KERNELBASE. @@ -51,20 +67,33 @@ * If you want to test if something's a kernel address, use is_kernel_addr(). */ -#define PAGE_OFFSET ASM_CONST(CONFIG_KERNEL_START) -#define KERNELBASE (PAGE_OFFSET + PHYSICAL_START) -#define LOAD_OFFSET PAGE_OFFSET +#define KERNELBASE ASM_CONST(CONFIG_KERNEL_START) +#define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET) +#define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START)) + +#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_FLATMEM) +#ifndef __ASSEMBLY__ +extern phys_addr_t memstart_addr; +extern phys_addr_t kernstart_addr; +#endif +#define PHYSICAL_START kernstart_addr +#define MEMORY_START memstart_addr +#else +#define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START) +#define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE) +#endif #ifdef CONFIG_FLATMEM -#define pfn_valid(pfn) ((pfn) < max_mapnr) +#define ARCH_PFN_OFFSET (MEMORY_START >> PAGE_SHIFT) +#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < (ARCH_PFN_OFFSET + max_mapnr)) #endif #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT) #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) -#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET)) -#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET) +#define __va(x) ((void *)((unsigned long)(x) - PHYSICAL_START + KERNELBASE)) +#define __pa(x) ((unsigned long)(x) + PHYSICAL_START - KERNELBASE) /* * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI, |